User:Shelly Livne/Targil 1 Ramachandran

דוגמאות לגרף רמצ'אנדראן של חלבונים שונים


Myoglobin מיוגלובין מבנה החלבון : המבנה השניוני של החלבון מורכב מסלילים של אלפא הליקס. גרף רמאצ'דראן : ניתן לראות מהגרף שרוב החומצות האמיניות שבחלבון נמצאות במבנה המתאים לאלפא הליקס. הנקודות האדומות החורגות מהתחום המוגדר, מתאימות כנראה למקטעים הנמצאים בקצוות האלפא הליקס. Red data points outside of the area expected for &alpha;-helix most likely involve residues at the end of the &alpha;-helix because often these have angle values that are not typical for &alpha;-helix. White points are those for loops and ordered, nonrepetitive structures. The few residues that map to the disallowed region are Gly. Return to model after viewing plot Concanavalin A View of structure : Twisted &beta;-sheet with small segments of &alpha;-helix. Ramachandran plot : Most of the yellow points are located in the area for twisted &beta;-sheets where one would expect them, and again the points in the disallowed region are Gly. Return to model after viewing plot. Acetylcholinesterase View structure Ramachandran Plot : Close to equal amounts of &alpha;-helix, &beta;-sheet, and ordered, nonrepetitive structures. One important exception to Gly in the disallowed region is Ser:200. Locate this residue that is located in a disallowed region (lower right quadrant). An interesting aspect concerning Ser:200 is that it is one of a triad of residues that are part of the catalytic site and are involved in the catalytic action of this enzyme. The unique &phi; and &psi; values for Ser:200 is the major factor in positioning the side chain so that it can participate in the catalysis. Return to model after viewing plot.